PDX1 and pancreatic neoplasm: Immunohistochemistry (IHC) sections were analyzed for F4/80+ immune cells in pancreatic tumors derived at equivalent endpoints from a pancreatic ductal adenocarcinoma cell (PDAC) model driven by pancreas-specific mutations in KRASG12D with either wild-type p53 (KC model; Pdx1-cre; LSL-KrasG12D/+) or one floxed Trp53 allele (KFC model; Pdx1-cre; LSL-KrasG12D/+; Trp53fl/+) (Tan et al., 2014) (Figure 1A, left).